Thermostat

module top_module (
    input too_cold,
    input too_hot,
    input mode,
    input fan_on,
    output heater,
    output aircon,
    output fan
); 
    // 控制加热器
    assign heater = mode & too_cold;

    // 控制空调
    assign aircon = ~mode & too_hot;

    // 控制风扇
    assign fan = (heater | aircon) | fan_on;
endmodule

以下是一些测试用例，验证逻辑是否正确：

mode	too_cold	too_hot	fan_on	heater	aircon	fan
1	1	0	0	1	0	1
1	0	0	0	0	0	0
0	0	1	0	0	1	1
0	0	0	0	0	0	0
0	0	0	1	0	0	1
1	1	0	1	1	0	1